1. Field of the Invention
The present invention generally relates to tape guide rollers and, more particularly, is directed to a tape guide roller for use in a tape transport portion of a tape recording and reproducing apparatus.
2. Description of the Prior Art
FIG. 1 schematically illustrates an example of a tape transport system of a tape recording and reproducing apparatus, e.g., an 8-mm video tape recorder (8-mm VTR).
In FIG. 1, reference numeral 1 depicts a tape cassette and reference numeral 2 a tape (magnetic tape) accommodated within the tape cassette 1. As shown in FIG. 1, in use, the tape 2 is withdrawn from the tape cassette 1 and wrapped around a magnetic head drum 3, thereby transported in this state. Further, in FIG. 1, reference numeral 4 depicts a tension regulator, 5 a capstan and 6 a pinch roller. Tape guide rollers 7 are disposed at both sides of the magnetic head drum 3 and the height of the tape 2 relative to the magnetic head drum 3 is regulated by these tape guide rollers 7.
FIG. 2 shows an arrangement of this kind of conventional tape guide roller 7.
As shown in FIG. 2, the tape guide roller 7 is composed of a roller 9 pivotally supported to a roller shaft 8, and upper and lower flanges 10 and 11 attached to the roller shaft 8 in the upper and lower positions of the roller 9. The tape guide roller 7 is secured to a base portion (not shown) of a tape recording and reproducing apparatus by means of a screw portion 12.
In use, the tape 2 is transported while in rotatable contact with the roller 9, and the height thereof is regulated by the upper flange 10 or by the lower flange 11. More specifically, in the illustrative example of FIG. 2, a lower end surface of the upper flange 10 serves as a tape regulating end face 13 and the height of the tape 2 is regulated by holding a tape edge (edge portion) of the tape 2 by the tape regulating end face 13.
The tape guide roller 7 thus arranged regulates the height of the tape 2 only by the tape regulating end face 13 of the upper flange 10 so that, if a tape is thin or if a tape is weak in strength, then the tape 2 will be easily buckled at its tape edge by a tape regulating force applied thereto from the tape regulating end face 13 of the upper flange 10 as shown in FIG. 3. Accordingly, it is to be noted that this conventional tape guide roller 7 is not sufficiently designed so as to prevent the tape from being damaged, broken or crinkled. Furthermore, in order to keep the stability of the tape transport system without tape damage or the like, the tape path must be adjusted with high accuracy, which is very difficult in actual practice, and the assembly parts must be produced at high accuracy.